1. Field of the Invention
This invention relates to a toolholder for holding a cutting tool. More particularly, this invention relates to a toolholder for holding a cutting tool in which the toolholder has a recessed groove to expose a portion of the underside of a flange on the cutting tool to assist in the removal of the cutting tool from the toolholder.
2. Description of the Prior Art
Rotatable cutting tools in toolholders have been common in the mining and construction industry for many years. However, one difficulty with these cutting tools occurs when the cutting tool is damaged or worn out and must be removed from the toolholder for replacement. One method for removing such a cutting tool involves striking the rear of the tool through the holder bore. However, on many machines using such toolholders, access to the rear of the holder bore is limited. A second method for removing the cutting tool involves the use of a hydraulic cylinder and pressure device which utilizes a wrench that slides into a groove on the head of the tool which by striking, physically forces the cutting tool from the toolholder. Both of these methods are slow and require extra equipment. Furthermore, both of these methods require an operator with training and experience.
U.S. application Ser. No. 09/166,634, filed Oct. 5, 1998 entitled "Cutting Bit Support Member With Undercut Flange For Removal" is co-pending and directed to a sleeve or a block for holding a cutting tool whereby the sleeve or block has an undercut portion to ease removal of the sleeve from a toolholder or removal of the block from a holder.
U.S. Pat. No. 5,374,111 entitled "Extraction Undercut For Flange Bits" and assigned to Kennametal Inc., the assignee of the current application, is hereby incorporated by reference and addresses the use of a rotatable cutting tool having a flange with an undercut whereby the undercut may be employed in conjunction with a prying tool to remove the rotatable cutting tool from the toolholder. Although it is relatively common to employ some sort of prying tool to physically remove a cutting bit from a toolholder, and such an undercut makes the removal of the cutting bit easier, the amount of material removed from the flange to form the undercut in limited because the structural integrity of the flange must be maintained when the force of the prying tool is applied against the flange.
The inventors of the subject application, realizing the need for easier removal of cutting tools from toolholders without removing material from the cutting bit flange, have sought a solution.